The invention concerns a multiple stage air-intake filter apparatus which includes a porous filter element in-line with a pre-cleaner cap.
Many machines require an air-intake filter apparatus to separate out undesirable substances before the air enters the machine. Examples of these types of filters include air-intake filters for blowers, compressors and vacuum pumps. Additionally, internal combustion engines require air-intake filters. Air-intake filters have to accomplish two opposing objectives. First, the filters need to permit high volume and high velocity uptake of air. Second, the filters need to remove unwanted substances from the uptaken air. The objective of substance removal inhibits the objective of high volume and high velocity air uptake. Industry, to balance the objectives, uses costly and complex filter elements having various combinations of material and shapes. Industry for instance, uses corrugations to increase the amount of pores available in a given area occupied by a filter media. Industry also uses multiple layer filter media.
To reduce the inconvenience and expense associated with replacing costly filter elements, it is advantageous to increase the longevity of the filter element. To increase longevity one could use a pre-cleaner. Pre-cleaners increase longevity of by removing larger contaminants from the air prior to the air""s passage through the air filter media.
Literature discloses a multiple stage air-intake filter apparatus. The filter apparatus has a pre-cleaner. The pre-cleaner defines an air pathway into a cylindrical filter housing. The filter housing encloses an outside-in cylindrical filter media. The cylindrical filter housing discharges air in a pathway which is perpendicular to the air pathway leading into the cylindrical housing. It is believed the filter has problems: small particles, in an amount greater than desired, may be discharged from the cylindrical housing into the associated machine. Reducing the size of the filter pores has problems; it impedes air flow.
The present invention provides a multiple stage air-intake filter which desires to produce improved air filtration without unduly impeding airflow. The invention includes a filter having a first stage construction to pre-clean air. In the first stage construction, an air-uptake portal receives cleaned air from a first stage separation chamber. The air received by the air-uptake portal passes through a fluid carrying juncture and to a second stage. The air enters the second stage through a second stage air-inlet. The second stage contains one or more filter elements. The pre-cleaned air passes through the filter elements and exits the multiple stage filter through a second stage air-outlet. The second stage air-outlet is in-line with the air-uptake portal, the second stage air-inlet, and the fluid carrying juncture. Having the air-uptake portal, second stage air-inlet, and fluid carrying juncture, in-line with the second stage outlet, improves air flow efficiency. The efficiency of the flow increases so much that dual filter elements, having relatively smaller pores, can be used. Thus the efficiency of the filter is improved. Additionally, having the in-line arrangement allows for a compact multiple stage air filter.
In accordance with the above desire, the multiple stage air-intake filter apparatus includes a first stage housing. The first stage housing has an end wall and a sidewall. The side wall has a first end and a second end. The end wall is disposed at the first end of the sidewall. The second end of the sidewall forms a first stage opening into a first stage hollow. The hollow is formed by the sidewall and the endwall. At least one vent opens into the sidewall. A fluid carrying juncture passes air from the first stage to a second stage housing.
The second stage housing forms a second stage hollow. The second stage housing has an air-inlet opening into the second stage hollow. The second stage housing has an air outlet opening out of said second stage hollow. The second stage air inlet is downstream of the fluid carrying juncture. The second stage air-outlet is downstream of the second stage air-inlet. The first stage opening which opens into said first stage hollow; said fluid carrying junction air uptake portal; said second stage air-inlet and said second stage air-outlet are all in fluid communication. The second stage air-inlet and second stage air-outlet are oriented so that a longitudinal axis, coextensive with an axis of the second stage out-let, passes through said second stage air-inlet.
These and other features of the invention will be apparent to those skilled in the art when the specification is read in conjunction with the drawings. It being expressly understood, however, that the drawings are for purposes of illustration only and are not intended as a definition of the limits of the invention.